PARTIALLY ORDERED TWO-WAY BÜCHI AUTOMATA

Partially Ordered Two-Way Büchi Automata

We introduce partially ordered two-way Büchi automata and characterize their expressive power in terms of fragments of first-order logic FO[<]. Partially ordered two-way Büchi automata are Büchi automata which can change the direction in which the input is processed with the constraint that whenever a state is left, it is never re-entered again. Nondeterministic partially ordered two-way Büchi ...

Partially-Ordered Two-Way Automata: A New Characterization of DA

A note on partially ordered tree automata

Automata for Partially Ordered and Partially Reliable Connections

We present a formal model for the speciication of a transport protocol with partially ordered and partially reliable data delivery. An abstract syntax is deened to specify order and reliability constraints in data ows, and is also used to specify the particular automata which recognise exactly the sets of deliverable streams. This new class of automata extends the Asynchronous Cellular Automata...

Two-Way Two-Tape Automata

In this article we consider two-way two-tape (alternating) automata accepting pairs of words and we study some closure properties of this model. Our main result is that such alternating automata are not closed under complementation for non-unary alphabets. This improves a similar result of Kari and Moore for picture languages. We also show that these deterministic, non-deterministic and alterna...